The positioning of mobile stations which make use of inherent information such as received transmission power is previously known. It is also known in prior art to make use of such information from different base stations receiving signals transmitted from a mobile station for increasing the accuracy of the positioning of the mobile station by means of triangulation.
There is an increasing demand for positioning from various administrations. Positioning is particularly requested for emergency calls. Accuracy and time to first fix are key parameters in positioning.
For GSM and UMTS there are two methods of positioning of consideration:                1. Cell Global Identity with Timing Advance.        2. Assisted GPS.        
Cell Global Identity with Timing Advance is operable with GSM. It makes use of a Cell Global Identity broadcast from each base station. The Cell Global Identity consequently identifies the base station with which the mobile station is communicating or the cell on which the mobile station is camping. The distance from the base station is determined by means of a system inherent Timing Advance parameter, which compensates for propagation delay time between a base station and a mobile station. Conclusively, with Cell Global Identity with Timing Advance, the mobile station can be determined to be within a ring-shaped or arc-shaped area within a cell or cell sector, depending on the radiation pattern. FIG. 1 illustrates positioning with timing advance for a 120° sector cell with a base station <<Site>> located within a cell <<Cell/Sector>> corner. A mobile station <<MS>> is located within a TA band <<TA BAND>> of width equal to the inaccuracy of the timing advance. However, the method does not reveal where within this band the mobile station is located unless more base stations are involved in positioning. Specifically, the mobile station <<MS>> could be anywhere in the shaded area <<TA BAND>> with the same outcome when trying to position it. In UMTS, a feature corresponding to Cell Global Identity with Timing Advance is named Cell Identity with Round Trip Time.
Assisted GPS is a satellite positioning system for assisting both GSM and UMTS, as well as optionally other terrestrial radio systems, but requires a GPS (Global Positioning System) receiver and additional signaling and is not compatible with old GSM terminals. A basic assisted GPS system is illustrated in FIG. 2. GPS position information is received from three satellites <<Sat1>>, <<Sat2>>, <<Sat3>>. To reduce time to first fix, GPS positioning is assisted by course terrestrial positioning communicated from base station <<Site>>. Basically, there are two modes of assisted operation, mobile assisted and mobile based. In the former mode, the mobile station determines pseudoranges to the satellites <<Sat1>>, <<Sat2>>, and <<Sat3>> in view as determined from the course positioning. The pseudoranges are transferred to the terrestrial network, in which the mobile station position is calculated. In the latter mode of assisted operation, the mobile station determines its position from available data obtained from the base station <<site>>.
U.S. Pat. No. 6,321,083 discloses a method and arrangement for locating a telephone traffic hot spot of a cell. The timing advance provides a mobile station distance from a base station with which it is connected. Direction to the mobile station is determined by means of signal strength from two or more adjacent cells.
International Patent Application W09728456 describes a terminal position location method using received power levels of multiple neighbor beams from an array antenna.
None of the cited documents above discloses using co-sited neighbor assisted positioning for determining a distance between a mobile station and a base station by means of timing advance and by determining a mobile station bearing from a received signal level and signal level received in a co-sited neighbor cell/sector, where preferably the signal levels are averaged levels.